Nissan Island Mollusca — Dell 
325 
TABLE 1 
Shell Data of Paludinella solomonensis n. sp. 
(Measurements in Millimeters) 
HOLOTYPE 
PARATYPE 
Height 
2.36 
2.77 
Diameter 
1.36 
1.91 
Height of Body Whorl . . 
1.91 
2.08 
Height of Aperture 
1.36 
1.41 
very well with P. keraudreni Vignard, the type 
species of the genus. This species occurs also 
in New Guinea (type locality), New Britain, 
and throughout the Solomons to Santa Anna 
in the southeast. Clench (1949: 33) notes that 
P. solomonensis Smith is very close to P. kerau- 
dreni. The differences given by Clench, larger 
size and dark coloration, do not appear very 
valid differences and probably only one form 
is represented. 
Sturanya modesta (Pfeiffer, 1853) 
This was the only member of the Heli- 
cinidae collected on Nissan. It was common 
throughout the island on low vegetation. 
Rensch and Rensch (1936: 683) record it 
from Shortland Island, New Georgia, Gua- 
dalcanal in the Solomons, the New Hebrides 
(type locality), and Samoa. 
Pseudocyclotus levis levis (Pfeiffer, 1855) 
This species occurred not uncommonly on 
Nissan on leaves of living vegetation. It oc- 
curs through the Solomons from the north to 
Santa Anna in the southeast. Rensch (1937: 
616) also records it from New Ireland. 
Omphalotropis nebulosa Pease, 1872 
Smith (1855: 597) has shown that nebulosa 
Pease should be used for the Solomon Island 
shells instead of bulimoides H. & J., which 
refers to a species from the Caroline Islands. 
Rensch and Rensch (1931: 684) have fol- 
lowed this usage. This species was commonly 
distributed under logs and leaves on the 
forest floor on Nissan. It appears to be dis- 
tributed throughout most of the Solomon 
Islands. It has also been recorded from the 
Bismarck Archipelago by Rensch (1937: 620). 
Paludinella solomonensis n. sp. 
Fig. id 
Shell small, 2.3 to 2.7 mm. long, globose, 
light brown in colour, smooth and semi- 
translucent. Protoconch of one and a half 
smooth shining whorls. Post nuclear whorls 
with very fine microscopic spirals on early 
whorls, becoming obsolete over adult whorl 
surfaces. Number of whorls five and a half. 
Outline of whorls rather broadly rounded. 
Body whorl slightly subangled below the 
middle. Sculpture consisting of irregular axial 
growth lines with traces of fine spirals on the 
base. Suture slightly impressed. Aperture ob- 
liquely ovate, constricted above. Outer lip 
thin, sharp. Parietal wall gently concave. 
Columella short, rounded. There is a well- 
marked constriction of the aperture edge at 
junction of parietal wall and columella. Um- 
bilicus completely obscured by thickened 
columella. Shell measurements are given in 
Table 1. 
Locality: Near lagoon shore, Tangalan Planta- 
tion, Nissan Island. R. K. Dell, 1944. 
Holotype (M. F. 2509) and paratype (M. F. 
2510) in Dominion Museum, Wellington, 
New Zealand. 
This appears to be the first record of the 
genus from the Solomons. The outline char- 
acterizes the species. 
Syncera nitida guamensis Abbott, 1949 
Fig. 1 h 
A series of shells from near the lagoon 
shore, Tangalan Plantation, Nissan Island, 
cannot be separated from the above sub- 
species from the Marianas. The umbilicus is 
totally closed in all the specimens seen. Half- 
grown specimens have a low spiral carina on 
the base. Abbott’s figure (1949, fig. 8) of 
